It is recognized in the water treatment industry that water analysis to determine the degree of water purity must often be conducted by personnel that are not of high chemical skill. As a result, the test methods must be as foolproof as possible. The testing of municipal water, waste water, industrial waters and environmental waters frequently involve tests, such as chlorine testing, iron testing, phosphate testing, pH testing, ammonium testing, nitrate testing and testing for certain indicator bacteria. These tests, to be reliably run, involve use of quantified amounts of test reagent added to carefully controlled amounts of aqueous test sample. In this way, predictable physical and/or chemical changes, such as color changes, etc., can be measured that will then allow determination of the presence and amount of the target analyte. Typically, in such reactions dry test reagent is added in the form of "pillows" of solid reagent which are opened and then the contents dumped into a reagent test tube containing the aqueous water sample. The problem with use of reagent "pillows" is that while the "pillow" itself contains the precise amount needed, to accurately test a defined amount of aqueous solution, the reagent, after opening the "pillow", can come in contact with the operator's hands, can be spilled, or can have adulterating contaminants accidentally added. This creates significant chances for error. If error in the amount or condition of reagent added occurs, the test result, i.e. the conclusion reached based upon the test reaction itself, is subject to error. These errors can result in unnecessary, and at times even dangerous changes in water processing conditions predicated upon false readings.
The potential for reagent contact with the operator, either through spills onto the hands or through inhalation of dust, is a significant safety hazard. While it is good chemical hygiene to avoid contact altogether, in practice it is nearly impossible to eliminate some contact when transferring reagents. This inadvertent contact can severely affect operators who may exhibit allergic reaction to the specific chemical.
In the past, it has been known that dry test reagents and aqueous test sample can be separated, one from another, by a water soluble test membrane. See, for example, Deutsch et al., U.S. Pat. No. 4,522,923, issued Jun. 11, 1985, that relates to a sample of biological fluid and water with the aqueous sample flowing to each successive chamber, with the chambers separated by water soluble polymer layers that are dissolved. This patent and the test system are designed for home pregnancy testing. Such a contained membrane separated system never before has been applied to water testing, and never before has been designed to provide a packaging system that allows for protection of the water soluble film prior to use in an aqueous test system, such that it minimizes the risk of damage to the water soluble membrane prior to test use.
There is, therefore, a continuing need to develop a touch-free water test system. By touch-free, it is meant that the testing reagents and the aqueous sample are all contained in a closed system, and the test operator need merely intermix those. This full containment of all reagents inside of a closed system as is self evident, would result in less error risk and false readings in addition to eliminating the chemical contact hazard to the operator. This invention has, as its primary objective, the fulfillment of the above need for a touch-free system in the context of water testing.
Another objective of the present invention is to provide a water treatment packaging system that is touch-free and, which at the same time, provides package protection of a water soluble separating membrane such that its risk of damage prior to test use is minimized.
A yet further objective of the invention is to provide a method of testing of water which is human touch-free with respect to all reagents in the system in order to minimize false readings or errors in test results.
A further objective of the invention is to provide a human touch-free method to eliminate chemical reagent contact hazard, thus enhancing the safety aspect of the test system.
The method of accomplishing these and other objectives of the invention will become apparent from the following description of the invention.